Gas Chromatography Essay

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Chromatography is a separation method used to help identify mixtures. One common form of chromatography is gas chromatography. This type of chromatography will usually use a gas as the mobile phase, and a liquid as the stationary phase (“Gas Chromatography”). A gas chromatograph is comprised of some vital components, which include: the carrier gas, flow controller, injector port, column, column oven, detector, and recorder (“Gas Chromatography”). The purpose of this lab was for an unknown accelerant to be identified using GCMS. Though this was not possible as the GCMS was not available. Instead, data samples were given for the use of determining the unknown accelerant.
Though the GCMS instrument was not used, there are procedures which
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Two glass vials should have then been labeled with the sample type. Using tweezers, the charcoals were removed from their containers, one at a time. The charcoal strips were cut into pieces with scissors. The charcoal strip pieces were then placed in the correctly labeled vials. These vials were taken to the fume hood, where 100 μL of carbon disulfide was added to each vial. More carbon disulfide was added if the charcoal strip was not fully covered. The vials were then capped and agitated for fifteen minutes. The samples were ran, and the data was recorded.
The unknown sample which was used for this experiment was Unknown #2, from Data Sets 3 and 4. The retention time on the peak chosen for Unknown #2 was 2.319 min. The closest result comparisons were Hexaborane, 1-Carbahexaborane(7), and Pentaborane(9).

Figure 1 Unknown Sample Peaks Figure 2 Unknown MS Spectra The retention time for the peak chosen in the lighter fluid sample was 2.358 min. The top three result comparisons were Hexaborane, 1-Carbahexaborane (7), and 6-Deoxy-D-mannono-4-lactone.
Figure 3 Lighter Fluid Peaks Figure 4 Lighter Fluid MS Spectra The retention time in the peak chosen for the nail polish remover was 2.328 min, while the closest result comparisons were Hexaborane, 1-Carbahexaborane(7), and 2-chloro-Pronoic acid.
Figure 5 Nail Polish Remover
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By looking at the MS Spectras of the unknown and lighter fluid sample, they are very similar. The MS Spectra for the unknown matches MS spectra of nail polish remover, but not as well. Many of the matches for the lighter fluid were also the same ones for the unknown. Though it cannot be positively determined that the unknown sample was lighter fluid since the data from the unknown and the data from the lighter fluid are not completely the same. A number of errors could have been made as the samples were not personally ran because of the unavailable use of the GCMS. This would count for any inconsistencies in the experiment. It is important to have a control in an experiment as it helps by establishing a baseline data which could be used for comparison. The peaks in the data were chosen because they were usually the tallest peaks, therefore the most visible, as the other peaks were small. Though the matches that were given for lighter fluid did not help, as not one of them was a components of lighter fluid, they were still the most similar to the unknown’s matches. This experiment may need to be repeated for more accurate results, especially since the GCMS instrument was not

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